Brain : a journal of neurology
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Deposits of amyloid beta-protein (Abeta) in neuritic plaques and cerebral vessels are a pathological hallmark of Alzheimer's disease. Fibrillar Abeta deposits are closely associated with inflammatory responses such as activated microglia in brain with this disease. Increasing lines of evidence support the hypothesis that activated microglia, innate immune cells in the CNS, play a pivotal role in the progression of the disease: either clearing Abeta deposits by phagocytic activity or releasing cytotoxic substances and pro-inflammatory cytokines. ⋯ Consistent with these observations in vivo, cultured microglia derived from Tlr(Lps-d)/Tlr(Lps-d) mice failed to show an increase in Abeta uptake after stimulation with a TLR4 ligand but not with a TLR9 ligand in vitro. Furthermore, activation of microglia (BV-2 cell) with a TLR2, TLR4 or TLR9 ligand, markedly boosted ingestion of Abeta in vitro. These results suggest that TLR signalling pathway(s) may be involved in clearance of Abeta-deposits in the brain and that TLRs can be a therapeutic target for Alzheimer's disease.
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Amyloid plaques and neurofibrillary tangles are key pathological features of Alzheimer's disease. Alzheimer's disease pathology is also characterized by neuroinflammation and neuronal degeneration, with the proteins associated with inflammatory responses being found in tight association with the plaques. One such protein is the serine protease inhibitor alpha-1-antichymotrypsin (ACT). ⋯ The ACT-treated neurons showed neurite loss and subsequently underwent apoptosis. Approximately 40-50% of neurons were TUNEL positive by 6 and at 24 h >70% of the neurons showed staining suggesting that ACT was inducing apoptosis in these neurons. These findings indicate that inappropriate inflammatory responses are a potential threat to the brain and that intervention directed at inhibiting the expression or function of ACT could be of therapeutic value in neurodegenerative diseases such as Alzheimer's and other tauopathies.
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Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic features (SUNA) are described, although SUNA is rarely reported. The phenotype of SUNCT and SUNA was characterized from a large series of patients (43 SUNCT, 9 SUNA). Three attack types were identified: stabs, groups of stabs and saw-tooth attacks. ⋯ The majority (95% SUNCT and 89% SUNA) had no refractory period between attacks. For SUNCT 58% and for SUNA 56% of patients were agitated with the attacks. We propose a new set of diagnostic criteria for these syndromes to better encompass the clinical presentations and which include a wider range of attack length, wider trigeminal pain distribution, cutaneous triggering and lack of refractory period.
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By far the largest known kindred with an inherited prion disease caused by a prion protein (PrP) octapeptide repeat insertion mutation originates from southeast England. This extended family shows very marked phenotypic heterogeneity and provides a unique opportunity to characterize this diversity and examine possible modifying factors amongst a large number of individuals in whom prion disease has been initiated by the same defined genetic mutation. As the inherited prion diseases comprise a significant proportion of familial early-onset dementia, an appreciation of their wide range of clinical presentation is important for differential diagnosis. ⋯ The transmission characteristics of prions from affected individuals resembled those of classical sporadic Creutzfeldt-Jakob disease. One surprising finding was a strong inverse correlation between age of onset and disease duration. The PrP gene polymorphic codon 129 was found to confer 41% of the variance in age of onset but interestingly this polymorphism had no effect on disease duration suggesting different molecular mechanisms are involved in determining disease onset and rate of clinical progression.
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Empathy is a complex form of psychological inference that enables us to understand the personal experience of another person through cognitive/evaluative and affective processes. Recent findings suggest that empathy for pain may involve a 'mirror-matching' simulation of the affective and sensory features of others' pain. Despite such evidence for a shared representation of self and other pain at the neural level, the possible influence of the observer's own sensitivity to pain upon his perception of others' pain has not been investigated yet. ⋯ Interestingly, pain judgements, inferred either from facial pain expressions or from pain-inducing events, were strongly related to inter-individual differences in emotional empathy among CIP patients, while such correlation between pain judgement and empathy was not found in control subjects. The results suggest that a normal personal experience of pain is not necessarily required for perceiving and feeling empathy for others' pain. In the absence of functional somatic resonance mechanisms shaped by previous pain experiences, others' pain might be greatly underestimated, however, especially when emotional cues are lacking, unless the observer is endowed with sufficient empathic abilities to fully acknowledge the suffering experience of others in spite of his own insensitivity.